From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4E58C77B7F for ; Wed, 17 May 2023 12:42:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229529AbjEQMm0 (ORCPT ); Wed, 17 May 2023 08:42:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230231AbjEQMmO (ORCPT ); Wed, 17 May 2023 08:42:14 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CB151BF; Wed, 17 May 2023 05:42:14 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id d2e1a72fcca58-64384274895so497182b3a.2; Wed, 17 May 2023 05:42:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684327334; x=1686919334; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=2/0OAhjGOHrmxWrbN9W3gRqX+XIbc1pmgYwBMpZEkis=; b=Y2JdKOfL1Y+jzb6X3BwIf/rxj42QRt8mwa4OtrOo0pu0hjdph/vy9O7eH+P3bIA/Wu ObzfpTrmVyGvCJORHYgUYs63ox5JQQv/FRwl9SFocNMVExF5lLaAQG9UiPlCG0Jv7s8G 6LMlcqfLrmNaXeg0l4kft5e1G1DmFygQR4JE0vv3Dw0/+gu1CJglcwWjV9sAL777wQWF zgr7s1jXiNG48TH1iYBF9fwp0zpib2gLE8KvL3Jfux1bEOuSqajB7oeNgg7YzCJ1ehdo sLmmu6yhcGPYxOvDNgsmSJxp6ej8BVPuFWKC9iNYrKSmZJPY/iNfhZ4KCEtIKCuF6jQH +3FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684327334; x=1686919334; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2/0OAhjGOHrmxWrbN9W3gRqX+XIbc1pmgYwBMpZEkis=; b=RmG2sAtCxUGALczBSP0DB/C13TIwPnqdOtcUm2TMBZYVf72Kvb2UfK+sWwT+wMOb3E YDawev2Yq2QOEAGVDUM9VoUHu5YBhLDPOnnSbleximUlvAGJqpEYmfFl9qpVEMoLWdW0 Fifc239w3DEjxhJQpYTid/xjwJ8ErfSDIJ2TWvW4eJwD84ttQTq4W7TFZAwfoQhuaEuA 3z8kezc2knXTsTPoOjWiJy8pkI9nIZrMunQtqsMTWrd+Nv0oJZaRxOjVWj2brVwL49ns bQXB05QFX4YyEk4R7XiuHSnsp/lvDmA30T9UPGdsFF5hM1zX/2QJFY6vAyl1CGU+VUY2 J5pw== X-Gm-Message-State: AC+VfDw90wgJerrvxaud1oPY7oUm80haSgOWLCXf0iXtH2rmlcZWF6NF RaWBP7mX8rb4NubmVE1T3DU= X-Google-Smtp-Source: ACHHUZ5Xclg3N4WSLv1+naH6PK6QsV3ODhQj3peOYplty+jdFtJZ+SsKXw/ZRTCtlBayT25szg+Dxw== X-Received: by 2002:a05:6a00:1308:b0:647:f128:c4f5 with SMTP id j8-20020a056a00130800b00647f128c4f5mr873899pfu.22.1684327333721; Wed, 17 May 2023 05:42:13 -0700 (PDT) Received: from localhost.localdomain ([81.70.217.19]) by smtp.gmail.com with ESMTPSA id u23-20020aa78497000000b0064aea45b040sm9244224pfn.168.2023.05.17.05.42.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 May 2023 05:42:13 -0700 (PDT) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: kuba@kernel.org Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, dsahern@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Menglong Dong Subject: [PATCH net-next 2/3] net: tcp: send zero-window when no memory Date: Wed, 17 May 2023 20:42:00 +0800 Message-Id: <20230517124201.441634-3-imagedong@tencent.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230517124201.441634-1-imagedong@tencent.com> References: <20230517124201.441634-1-imagedong@tencent.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Menglong Dong For now, skb will be dropped when no memory, which makes client keep retrans util timeout and it's not friendly to the users. Therefore, now we force to receive one packet on current socket when the protocol memory is out of the limitation. Then, this socket will stay in 'no mem' status, util protocol memory is available. When a socket is in 'no mem' status, it's receive window will become 0, which means window shrink happens. And the sender need to handle such window shrink properly, which is done in the next commit. Signed-off-by: Menglong Dong --- include/net/sock.h | 1 + net/ipv4/tcp_input.c | 12 ++++++++++++ net/ipv4/tcp_output.c | 7 +++++++ 3 files changed, 20 insertions(+) diff --git a/include/net/sock.h b/include/net/sock.h index 5edf0038867c..90db8a1d7f31 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -957,6 +957,7 @@ enum sock_flags { SOCK_XDP, /* XDP is attached */ SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */ SOCK_RCVMARK, /* Receive SO_MARK ancillary data with packet */ + SOCK_NO_MEM, /* protocol memory limitation happened */ }; #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE)) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a057330d6f59..56e395cb4554 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5047,10 +5047,22 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) if (skb_queue_len(&sk->sk_receive_queue) == 0) sk_forced_mem_schedule(sk, skb->truesize); else if (tcp_try_rmem_schedule(sk, skb, skb->truesize)) { + if (sysctl_tcp_wnd_shrink) + goto do_wnd_shrink; + reason = SKB_DROP_REASON_PROTO_MEM; NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRCVQDROP); sk->sk_data_ready(sk); goto drop; +do_wnd_shrink: + if (sock_flag(sk, SOCK_NO_MEM)) { + NET_INC_STATS(sock_net(sk), + LINUX_MIB_TCPRCVQDROP); + sk->sk_data_ready(sk); + goto out_of_window; + } + sk_forced_mem_schedule(sk, skb->truesize); + sock_set_flag(sk, SOCK_NO_MEM); } eaten = tcp_queue_rcv(sk, skb, &fragstolen); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index cfe128b81a01..21dc4f7e0a12 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -300,6 +300,13 @@ static u16 tcp_select_window(struct sock *sk) NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFROMZEROWINDOWADV); } + if (sock_flag(sk, SOCK_NO_MEM)) { + if (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 2)) + sock_reset_flag(sk, SOCK_NO_MEM); + else + new_win = 0; + } + return new_win; } -- 2.40.1